Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
  • C07D401/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings
  • C07D401/12—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings linked by a chain containing hetero atoms as chain links
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D237/00—Heterocyclic compounds containing 1,2-diazine or hydrogenated 1,2-diazine rings
  • C07D237/02—Heterocyclic compounds containing 1,2-diazine or hydrogenated 1,2-diazine rings not condensed with other rings
  • C07D237/04—Heterocyclic compounds containing 1,2-diazine or hydrogenated 1,2-diazine rings not condensed with other rings having less than three double bonds between ring members or between ring members and non-ring members
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D403/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00
  • C07D403/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00 containing two hetero rings
  • C07D403/12—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00 containing two hetero rings linked by a chain containing hetero atoms as chain links

Definitions

• This invention relates to a novel pyridazinone derivatives, more specifically, to a pyridazinone compound represented by the following formula wherein Ar represents a group of the formula in which R', R 2 and R 3 may be identical or different and each represents a hydrogen atom, a lower alkyl group, a trifluoromethyl group, a halogen atom, a cyano group or a nitro group, R 4 represents a hydrogen atom or a lower alkyl group substituted by a carbamoyl group or a lower alkoxy group, and C * represents an asymmetric carbon atom. or a salt thereof, and to a hypotensive agent comprising a pyridazinone compound of formula (I) or a pharmaceutically acceptable salt thereof as an active ingredient.
• Ar represents a group of the formula in which R', R 2 and R 3 may be identical or different and each represents a hydrogen atom, a lower alkyl group, a trifluoromethyl group,
• Vasodilators which have been much used as hypotensive agents generally have an accurate hypotensive action, but have the defect of involving tachycardia.
• sympathetic nerve beta-receptor blocking (to be referred to as beta-blocking) agents are also used as hypotensive agents, and have teh advantage of not involving tachycardia. But their hypotensive action is slow-acting and weak.
• vasodilators and beta-blocking agents when administered alone, cannot be exptected to give a sufficient effect.
• hypotensive agent having the advantages of a vasodilator and the advantages of a beta-blocking agent.
• hypotensive agents which have both a beta-blocking action and a vasodilating action (for example, U. S. Patent 4,053,601 and Japanese Laid-Open Patent Publication No. 32489/1979). These publications show little data which will substantiate these actions.
• the compounds of formula (1) are especially useful as hypotensive agents which cause little tachycardia and have little effects on the heart.
• lower used to qualify a group or a compound means that a group or a compound so qualified has not more than 5, preferably not more than 3, carbon atoms.
• the "lower alkyl group” may be linear or branched, and includes, for example, methyl, ethyl, n-propyl, iso-propyl, n- iso-, sec- or tert-butyl group. Methyl and ethyl groups are especially preferred.
• lower alkoxy group are lower alkyloxy groups in which the lower alkyl moiety has the above meaning, and examples include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy groups.
• Specific examples of the lower alkyl group substituted by a lower alkoxy group or a carbamoyl group include 2-methoxyethyl, 2-ethoxyethyl, 3-methoxypropyl, tert-butoxymethyl carbamoyl methyl and 2-carbamoylethyl groups.
• the present invention also provide acid addition salts of the pyridazinone compounds of formula (I).
• the acid addition salts of the compounds of formula (I) are, for example, inorganic acid salts the compounds of formula (I), such as the hydrochlorides, hydrobromides, sulfates, nitrates, and phosphates, and their organic acid salts such as the acetates, propionates, citrates, lactates and tartrates. Of these, pharmaceutically acceptable acid addition salts are advantageously used.
• the pyridazinone derivatives of formula (I) may be produced by the reaction route shown in reaction scheme A.
• the reaction of the compound of formula (II) or its salt with compound of formula (III) may be carried out by dehydrocondensation generally in a suitable inert reaction medium, for example, water, an alcohol such as methanol or ethanol, a mixed solvent such as water-methanol.
• a suitable inert reaction medium for example, water, an alcohol such as methanol or ethanol, a mixed solvent such as water-methanol.
• the condensation is carried out under neutral or weakly alkaline, conditions.
• an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate or sodium hydrogen carbonate, to the reaction system.
• the dehydrocondensation reaction may proceed even in the absence of a catalyst.
• reaction promoter such as benzyl triethyl ammonium chloride, benzyl trimethyl ammonium chloride, tetrabutyl ammonium bromide.
• the amount of the reaction promoter is not especially limited. Usually, the suitable amount of the reaction promoter is 0.01 mole to 0.02 mole per mole of the compound of formula (II).
• the compound of formula (II) may be used in a free form. Generally, it is easy and convenient to handle if it is in the form of an acid addition salt, such as a hydrochloride.
• the proportion of the compound of formula (III) to the compound of formula (II) is not strictly and can be changed according to the reaction conditions.
• the proportion of the compound of formula (III) is suitably 1 to 5 moles, preferably 1 to 2 moles, per mole of the compound of formula (II).
• the reaction temperature in the dehydrocondensation is about 50 °C to the refluxing temperature of the reaction mixture, preferably the refluxing temperature.
• a compound of (IV) is formed. Since this compound precipitates as crystals when an acid is added to the reaction mixture, it is separated by such means as fil tration, and then reacted with hydrazibne hydrate usually in an aqueous medium to cyclize it. This reaction is carried out generally at a temperature of about 60 to about 100 C, preferably 80 to 100 ° C.
• the amount of the hydrazine hydrate is not particularly limited. Generally, the suitable amount of the hydrazine hydrate is 1 to 10 moles, preferably 2 to 5 moles, per mole of the compound of formula (IV).
• the compound of formula (V) obtained by the cylization reaction can then be changed to the compound of formula (VI) by hydrogenation.
• This hydrogenation can be carried out in a suitable inert medium such as an alcohol (e.g., methanol or ethanol), dimethylformamide or dimethylacetamide by contacting the compound of formula (VI) with hydrogen in the presence of a hydrogenation catalyst such as Raney nickel, palladium, or palladium-carbon.
• the pressure of hydrogen is generally 1 tc 100 atmospheres, preferably 1 to 10 atmospheres.
• the suitable reaction temperature is from room temperature to 70 C.
• the compound of formula (VI) is then reacted with a compound of formula (VII) to give the desired compound of formula (I).
• the reaction of the compound of formula (VI) with the compound of formula (VII) may be carried out in the absence of a solvent. Generally, it may be carried out in an inert medium, for example, an alcohol such as methanol, ethanol, propanol or butanol, an ether such as diethyl ether, dioxane, or tetrahydrofuran, an aromatic hydrocarbon such as benzene, toluene or xylene, or a halogenated hydrocarbon such as dichloromethane, chloroform or tetrachloroethane.
• the reaction temperature is not strictly limited.
• the amount of the compound of formula (VII) relative to the compound of formula (VI) can be varied over a wide range. Generally, it is advantageous to use 0.1 to 20 moles, preferably 0.2 to 5 moles, of the compound of formula (VII) per mole of the compound of formula (VI).
• the desired compound of formula (I) may be obtained in good yields.
• the recovery and purification of the compound of formula (I) from the reaction mixture may be carried out by known methods, such as extraction, column chromatography, thin-layer chromatography, and recrystallization.
• the epoxy compound of formula (VII) may be easily produced by reacting an epihalohydrin with the phenol derivative of formula (VIII) in accordance with the following reaction scheme B. wherein Hal represents a halogen atom, and Ar and C * are as defined above.
• the pyridazinone compound of formula (I) produced as above may be, as required, treated, by a known method, with an inorganic acid such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid or phosphoric acid, or an organic acid such as acetic acid, propionic acid, oxalic acid, maleic acid, citric acid, lactic acid, tartric acid or methanesulfonic acid to convert it to the corresponding salt.
• an inorganic acid such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid or phosphoric acid
• organic acid such as acetic acid, propionic acid, oxalic acid, maleic acid, citric acid, lactic acid, tartric acid or methanesulfonic acid
• the pydirazinone compound of formula (I) provided by this invention is therapeutically very good as a long-lasting hypotensive agent which has a beta-blocking action and a vasodilating action in a well-balanced combination and does not cause tachycardia.
• Pentobarbital(60 mg/kg, i.p.)-anaethetized rats (Wistar, male, body weight 350 - 420g), four per group, were used, and the blood pressure was measured by a pressure transducer connected via cannula inserted into the femoral artery.
• the heart rate was calculated from the blood pressure pulsating wave.
• Isoprenalin (0.1 microgram/kg i.v) was administered, and immediately after, the heart rate was measured and recorded. The measured value of the increase in heart rate at this time was H,.
• the test compound was suspended in 0.2 % Tween 80 - physiological saline, and the resulting suspension was administered through a cannula inserted into the femoral vein of the rat.
• the dose-reaction curve was prepared.
• the dose of the test compound was determined from the curve when the percent inhibition of the tachycardia became 50 %.
• the dose was compared with propranolol, and the results are shown in Table 1.
• Pentobarbital (60 mg/kg, i.p.)-anaethetized rats (Wister, male, body weight 350 - 420 g) 4 per group were used, and the blood pressure was measured by a pressure transducer connected via a cannula inserted in the femoral artery.
• the test compouind was suspended in 0.2 % Tween 80 - physiological saline, and the suspension was administered intravenously in a dose of 1 mg/kg.
• the blood pressure was measured and recorded before and 20 min. after the administration, and the difference was calculated to determine the hypotensive action of the test compound.
• compound A is considered to have a well-balanced combination of beta-blocking action and vasodilating action in comparison with the control compound (1).
• the hypotensive action and the heart rate change of compound A were measured by the following methods.
• the compounds of formula (I) provided by this invention have a well-balanced combination of beta-blocking action and vasodilating action, they may be administered orally or parenterally (for exmaple by intramuscular injection, intravenous injection, subcutaneous administration, intrarectal administration or sublingual administration) to man and other warm-blooded animals for the treatment of diseases of the cardiovascular system such as hypertension, heart failure, angina pectoris, cerebral vascular insufficiency, and arrhythmia.
• diseases of the cardiovascular system such as hypertension, heart failure, angina pectoris, cerebral vascular insufficiency, and arrhythmia.
• the compound of this invention may be formulated into various forms suitable for oral and parenteral administration.
• the compound of this invention may be formulated by using usually used nontoxic vehicles, binders, lubricants, disintegrants, antiseptics, isotonizing agents, stabilizers, dispersants, antioxidants, coloring agents, flavoring agents, and buffers.
• such drug may be prepared into a solid form (such as tablets, hard capsules, soft capsules, granules, powers, pellets, pills and trouches), a semisolid form (such as suppositories) and a liquid form (such as an injectable, an emulsion, a suspension and a syrup).
• non-toxic additives examples include starch, gelatin, glucose, lactose, fructose, maltose, magnesium carbonate, talc, magnesium stearate, methyl cellulose, carboxymethyl cellulose or its salts, gum arabic, polyethylene glycol, alkyl p-hydroxybenzoates, syrup, ethanol, propylene glycol, vaseline, carbowax, glycerol, sodium chloride, sodium sulfite, sodium phosphate and citric acid.
• the above drug may also contain a therapeutically useful drug.
• the amount of the compound of the invention in the drug varies according to its form. Desirably, it is 5 to 100 % by weight for the solid and semisoid forms, and 0.1 to 10 % by weight for the liquid form.
• the dose of the compound of this invention may be widely varied depending upon the type of the warm-blooded animal to which it is administered, the severity of the condition, or the diagnosis of the physician. Generally, it may be 0.02 to 30 mg/kg, preferably 0.05 to 10 mg/kg, per day. It may be administered in doses which are less than the lower limit specified above or larger than the above-specified upper limit depending upon the severity of the patient's condition or the physician's diagnosis. The above dose may be administered once daily or in several divided dosages per day.
• Examples of recipes of tablets containing 5 mg and 20 mg of the active component per tablet are as follows: The method of preaparation in detail was as follows:-(2S) or 6-[4-[2-(2S)-3-(5-chloro-2-cyanophenoxy)-2-hydroxypropylamino]-2-methylpropylamino]phenyl]-4,5-dihydro-3(2H)-pyridazinone or crystals of its optically active isomer were pulverized, and well mixed with lactose and starch. 10 % of starch paste was added to the mixed powder, and stirred with stirring to produce granules. After drying, the granules were adjusted to about 840 microns, and talc and magnesium stearate were mixed, and the mixture was tableted.

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• 1990
  • 1990-06-15 NZ NZ234087A patent/NZ234087A/xx unknown
  • 1990-06-18 AU AU57537/90A patent/AU622031B2/en not_active Ceased
  • 1990-06-18 US US07/539,741 patent/US5082844A/en not_active Expired - Fee Related
  • 1990-06-19 CA CA002019271A patent/CA2019271A1/fr not_active Abandoned
  • 1990-06-19 EP EP90111543A patent/EP0404050A1/fr not_active Ceased
• 1991
  • 1991-09-27 US US07/770,287 patent/US5130314A/en not_active Expired - Fee Related

Patent Citations (1)

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